Abstract

Hot isostatic pressing (HIP) of type 316 L stainless steel powder has been an established manufacturing practice for more than 25 years in the oil and gas sector and more recently in the naval defense sector. To demonstrate the capability of the powder metallurgy HIP (PM/HIP) for nuclear power applications, a systematic study of 316 L commercial powder production, encapsulation/consolidation providers, and selected HIP parameters was undertaken by the Nuclear AMRC in collaboration with the Electric Power Research Institute (EPRI). In this study, the 316 L powder specification limited the oxygen content of the powder to under 130 parts per million (ppm), which reflects the improvements that commercial powder suppliers have been making over the past decade to ensure greater powder cleanliness. The test program assessed powder supply, HIP service provider, and HIP sustain time. Excellent test results were achieved across the full range of variables studied with all billets meeting the specification requirements of ASTM A988 and additional requirements imposed based on nuclear manufacturing standards. Significantly, the study demonstrated the robustness of the PM/HIP supply chain, as material produced via differing HIP service providers resulted in very consistent material properties across the destructive test program. Furthermore, no significant difference in material properties was noted for material HIP between 2 and 8 h hold time, suggesting that the HIP process window is large. Both these results are significant from an end-user standpoint as they highlight the uniformity of the process through the full manufacturing cycle from powder procurement to destructive testing. Despite all material passing specification requirements, some property variation was noted for differing powder suppliers. Considering the systematic approach, this was attributed to powder composition, with both low oxygen and high nitrogen contents contributing to improvements in Charpy impact strength and tensile strength, respectively.

References

References
1.
ASME
,
2013
, “
ASME Boiler and Pressure Vessel Code Case N-83
4,” American Society of Mechanical Engineering, New York, Standard.
2.
Gandy
,
D.
,
Siefert
,
J.
,
Lherbier
,
L.
, and
Novotnak
,
D.
,
2014
, “
PM-HIP Research for Pressure Retaining Applications Within the Electric Power Industry
,”
ASME
Paper No. SMR 2014–3305.10.1115/SMR2014-3305
3.
Burdett
,
W. B.
,
Hurrell
,
P.
, and
Gilleland
,
A.
,
2004
, “
Hot Isostatic Pressing of Type 316 L Powder for Pressure Retaining Components
,”
ASME
Paper No. PVP2005-71711.10.1115/PVP2005-71711
4.
Burdett
,
W. B.
, and
Watson
,
C. T.
,
2005
, “
Hot Isostatic Pressing of a 316 L Powder for a Pressure Retaining Component
,”
ASME
Paper No. PVP2005-71711.
5.
Burdett
,
W. B.
, and
Hookham
,
I. D.
,
2009
, “
The Implementation of Hot Isostatically Pressed Powder Type 304 L/316 L Pressure Boundary Components in a PWR Plant
,”
ASME
Paper No. PVP2009-77199. 10.1115/PVP2009-77199
6.
Thomas
,
B.
, and
Martin
,
O.
,
2016
, “
Impact Toughness for PM HIP 316 L at Cryogenic Temperatures
,”
ASME
Paper No. PVP2016-64002. 10.1115/PVP2016-64002
7.
ASTM
, 2016, “
Standard Specification for Hot Isostatically Pressed Stainless Steel Flanges, Fittings, Valves, and Parts for High Temperature Service
,” ASTM International, West Conshohocken, PA, Standard No. A988/A988-16.
8.
Feichtinger
,
H. K.
,
1991
, “
Alternative Methods for the Production of High Nitrogen Stainless Steels
,”
International Conference on Stainless Steels
, Chiba, Japan, June 10–13, pp.
1125
1132
.
9.
Speidel
,
M. O.
,
2001
, “
Ultrahigh Strength Austenitic Stainless Steels
,” Stainless Steel World, The Hague, The Netherlands, Nov. 13–15, pp.
98
106
.
10.
Burdett
,
W. B.
,
2017
, personal communication.
11.
Cooper
,
A.
,
Cooper
,
N.
,
Dhers
,
J.
, and
Sherry
,
A.
,
2016
, “
Effect of Oxygen Content Upon the Microstructural and Mechanical Properties of Type 316 L Austenitic Stainless Steel Manufactured by Hot Isostatic Pressing
,”
Metall. Mater. Trans. A
,
47
, pp.
4467
4475
.10.1007/s11661-016-3612-6
12.
Lind
,
A.
, and
Sundstrom
,
J.
, “
The Effect of Reduced Oxygen Content Powder on the Impact Toughness of 316 Steel Powder Joined to 316 Steel by Low Temperature HIP
,” Studsvik Nuclear, Nykoping, Sweden, Report Nos. Studsvik/N-04/150, 2004-11-08.
13.
Gandy
,
D.
, personal communication.
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